hwmon: Drop reference to Jean's tree

This tree has not been used for over a year, Guenter is taking all
the hwmon patches in practice.

Signed-off-by: Jean Delvare <jdelvare@suse.de>
Cc: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>